Hi - my name is A. and I am a mom of two children, ages 20 and 21, and a mom of FIVE dogs! I am the President of a non-profit, breed specific rescue (Kentuckiana Pug Rescue). We deal with dogs that are not housebroken at older ages ALL the time. The first thing I would do is take the dog to the vet and make sure there are NO medical problems causing this - they will urinate everywhere if they have a bladder or kidney infection - and this is especially common as the cause of a untrained female. Buy a crate! Crate training is the easiest way to housebreak a dog. When you can keep a direct eye on the dog, it can be out of the crate, when you can't, like when you are taking a shower...into the crate it goes. You just start all over, like the dog is a puppy. The key is it can only be out when you are keeping a direct eye on it, so that you can get it outside if it starts to show signs that it needs to go (circling, sniffing and looking for a spot to go potty). When the dog is outside, you need to watch it to make sure it is doing what it should be doing - Remember to praise heavily, and maybe give a treat, each and every time he goes. Some people think crates are cruel, but they are like a bedroom to a dog - they are a safety zone. They may not like it at first, but once they get used to it (and just like with your kids, you have to hang tough for three or so days to get them used to the crate) the crate will be THEIR space and they will love it. Mine are in their crates all the time - we leave the doors open and they go in there and take naps all the time.
A couple of tips - if this is a male dog, they make a thing called a belly band. Google it, and you will get lots of sites, essentially a male dog diaper, helps to save your furniture. AND - HYDROGEN PEROXIDE, which is the main cleaning ingredient in cleaners like Oxy Clean. It does not bleach (I have a red sofa and use it all the time)unless it has a bleaching agent added to it - but it DOES clean up the stain and the smell of ANY bodily fluid. Blot as much of the urine up as you can, and then DUMP and I mean DUMP the peroxide on the stain. It should be completely saturated and then some - it will evaporate and take the stain and smell right with it!!
Good luck - it CAN be done!